1. Field of the Invention
The example embodiments relate to a thin film transistor (TFT) using a conductive carbon nano tube (CNT) and a semiconductive CNT, and more particularly, to a flexible and transparent TFT.
2. Description of the Related Art
A thin film transistor (TFT) is an important semiconductor device that is essential in a display field, and studies are being performed on such a TFT as a core device in a flexible electronics field that has recently come into the spotlight.
Currently, a carbon nano tube (CNT) has an excellent charge transmission characteristic and a large aspect ratio, and thus has both high charge mobility and transparency by obtaining a plurality of charge transmission paths. Moreover, the CNT has excellent elasticity, and thus is electrically and mechanically stable to the bending. Accordingly, the CNT is noticed as an element of the TFT.
A flexible electronics field includes a paper display, a foldable display, etc. Since a display must be freely folded or rolled up, all devices used in the display must be flexible. An important and main device of such flexible devices is a TFT that is mainly prepared by using an organic material. An organic TFT has a low production cost and is flexible, but has remarkably low charge mobility and switching speed compared to a polycrystal silicon TFT, and thus is difficult to be applied to a device that requires high charge mobility and high switching speed. Also, since the organic TFT partially includes an opaque element, studies on maintaining a flexible and stable electric characteristic while having a transparent structure are required to be performed, so as to be applied to the paper display, or the like.
Meanwhile, the paper display and the foldable display use a flexible substrate that is formed of plastic. However, since the plastic is semi-permanent that is difficult to be naturally degraded, using the plastic in the flexible substrate may cause an environmental pollution.